Diuretics of the chlorobenzenesulfonamide type containing a free carboxy group on the benzene ring (DE-OS Nos. 1,122,541 and 2,247,828), carboxylic acid amide group (DE-OS No. 1,158,927) or carboxylic acid hydrazide group (Hungarian Pat. Nos. 150,352 and 152,300) have earlier been described. Thus, Furosemide from the first group (DE-PS No. 1,122,541; and K. Sturm, et al.: Chem. Ber. 99, 328 (1966)), Diapamide from the second group (L. T. Blouin et al.: J. New Drugs 3, 302 (1963)) and Clopamide from the third group (E. Jucker et al.: Arzneim.-Forsch. 13, 269 (1963)/have all become well-known drugs.
The chemical structure of the compounds according to the present invention significantly differs from those of the known diuretics mentioned above.
Benzimidazole type derivatives having diuretic effect have been described in U.S. Pat. No. 4,420,487; however, these compounds do not contain a benzoic acid hydrazide moiety and thus their structure is significantly different from that of the compounds according to the invention.